Here is a list of 5 interesting facts about June 23 in Arizona history based on the available sources:

1. On June 23, 1910, a wildfire broke out near the town of Flagstaff which destroyed over 200 buildings and left thousands of people homeless. The blaze was reportedly started by a railroad worker's spark and spread quickly as the area had experienced a drought and strong winds.

2. June 23, 1930, marked the opening of the Hoover Dam, which was built along the Arizona-Nevada border on the Colorado River. The construction of the dam (originally named Boulder Dam) began in 1931 and was one of the largest government projects during the Great Depression, providing thousands of jobs and electricity to the western United States.

3. In 1964, the first-ever Navajo Tribal Fair was held in Window Rock, Arizona, on June 23. The event showcased traditional Navajo arts, crafts, and competitions, as well as modern entertainment and rodeo performances. The fair has since become an annual event and attracts visitors from all over the world.

4. On June 23, 1972, President Richard Nixon signed the Comprehensive Employment and Training Act (CETA) into law. The act provided federal funding for job training and employment programs across the country, including in Arizona, where it helped thousands of people find work and further their careers.

5. In 1997, the Phoenix Suns basketball team drafted future NBA All-Star Steve Nash on June 23. Nash played for the Suns for several seasons and helped the team reach the playoffs multiple times. He later became a two-time NBA Most Valuable Player and retired in 2015 after a 19-year career.